P1.07-034 Somatostatin Receptors Expression in Small Cell Lung Cancer Patients: Topic: Molecular Changes

Somatostatin receptors have been described on the membrane of neoplastic cells and their expression has also been demonstrated on small cell lung cancer (SCLC). In this study we examined if the expression of somatostatin receptors at the time of disease progression correlated with survival and time to progression (TTP) of SCLC patients. 10 patients with SCLC were studied using 111In-octreotide (111In-OCT) scintigraphy at diagnosis and disease progression. Scintigraphic examinations were performed following intravenous (i.v.) injection of 111 MBq 111In-OCT with whole-body scintigraphy and planar scintigraphy of the thorax as well as the SPECT technique .The scintigraphic results were expressed in comparison with soft tissue intake (normal prices <1.5). 111In-OCT was positive in all 10 SCLC patients at the time of diagnosis and progression of the disease. No statistical correlation was found between somatostatin receptors expression at the progression- mainly subtype 2 (SSTR 2)- and survival (p=0.43), nor TTP (p=0.25). Also the difference in somatostatin receptors expression during diagnosis and progression had no statistical correlation with survival and TTP. The clinical utility of receptor status characterization obtained with 111In-OCT scintigraphy is rather confined. Our study shows that 111In-OCT scintigraphy, although is a reliable, non-invasive technique to detect primary SLCL and its locoregional or distant metastases, cannot be used as a prognostic or predictive factor in SCLC patients.